Generalized slave-particle method for extended Hubbard models

TL;DR

This paper presents a flexible generalized slave-particle framework for extended Hubbard models, unifying existing methods and improving physical accuracy at weak correlations by eliminating unphysical states.

Contribution

It introduces a unified, adaptable slave-particle approach that encompasses recent methods and allows selective treatment of electronic degrees of freedom.

Findings

Includes slave-rotor and slave-spin methods as special cases

Removes unphysical states at weak correlation strengths

Provides a flexible formalism for studying correlation effects

Abstract

We introduce a set of generalized slave-particle models for extended Hubbard models that treat localized electronic correlations using slave-boson decompositions. Our models automatically include two slave-particle methods of recent interest, the slave-rotor and slave-spin methods, as well as a ladder of new intermediate models where one can choose which of the electronic degrees of freedom (e.g., spin or orbital labels) are treated as correlated degrees of freedom by the slave bosons. In addition, our method removes the aberrant behavior of the slave-rotor model at weak correlation strength by removing the contribution of unphysical states from the bosonic Hilbert space. The flexibility of our formalism permits one to separate and isolate the effect of correlations on the key degrees of freedom.